The Tomography/Data Analysis Core provides the means necessary to perform the acquisition, work-up, and analysis of all positron emission tomographic (PET), single photon emission tomographic )SPECT) and magnetic resonance imaging (MRI) data generated from this program project grant. The Core has five principle functions: 1) a patient studies component to facilitate the acquisition and work-up of human PET studies; 2) compartmental analysis and parameter estimation component to provide parametric measures for quantification of important biochemical and physiological parameters from dynamic PET/SPECT data; 3) a data analysis component to facilitate the extraction of quantitative information from PET images for subsequent analysis, and to use magnetic resonance (MR) imaging for the purpose of combining anatomic and functional information including reorientation of data into a stereotactic reference system, the inverse mapping of stereotactically defined volumes-of-interest into the individual subject's frame of reference, as well as assessment of partial volume effects and tissue atrophy on the quantitative PET and SPECT data; 4) a data management component for efficient handling and storage of the large quantities of data that will be generated from the studies proposed in the grant application; and 5) a statistical analysis component that will be responsible for providing expertise in statistical matters for both experimental design and subsequent analysis of the data acquired in these projects. The personnel participating in the Tomography/Data Analysis Core will interact closely with the investigators of each of the individual projects. All projects will require the facilities developed in each component of this Core. Besides providing these basic services, the Core will also address specific scanning and data analysis issues that arise within the individual projects.